Help identifying 904 low gear set components

The low gear set shell will have a larger sun gear on the inside and a smaller one on the outside. The planetary sets will only fit the proper sun gear. All the stock ones I've seen are the same angle. Some have 4 planetary gears and others have 3, some have aluminum carriers and others steel, we prefer the steel ones for the strength. The ring gear and the planetarys should be one unit held together by a snap ring. They will fit in any 904. You may want to look for the 5 clutch front drum also, this is the weak link in these transmissions, you do need the proper front pump from a non lock up unit to make it fit. All these parts can be found in some 999's, but from the outside they all look the same. The gear sets have been around since the early seventies. I'm not sure if the gears from the O.D. units will work.